Counting carbs may help with type 1 diabetes

NEW YORK (Reuters Health) - Tallying the number of carbohydrates in the diet may be helpful to people using an insulin pump to treat type 1 diabetes, a small study suggests.

The study, of 61 adults on insulin pump therapy, found that those who learned to count carbs had a small reduction in weight and waist size after 6 months.

They also reported gains in quality of life and -- at least for those who consistently counted their carbs with each meal -- an improvement in blood sugar levels.

The findings, published online by the journal Diabetes Care and scheduled to appear in the April print issue, do not prove that carb counting is the answer for people with type 1 diabetes.

But it is widely recommended that people on insulin try to estimate the carbohydrate content of their meals to help calculate their insulin doses, said Dr. Sanjeev Mehta, of the Joslin Diabetes Center and Harvard Medical School in Boston.

Carbohydrate counting is one way to do that, noted Mehta, who was not involved in the study.

Other ways include paying close attention to portion size, using diabetes "exchange lists" and choosing foods based on "glycemic index" -- a measure of how far and how fast a given foods sends up blood sugar.

"There is no definitive data to suggest the superiority of one method over another in terms of ease of use or (blood sugar) control," Mehta told Reuters Health in an email.

A few studies have suggested that carbohydrate counting can help people with type 1 diabetes control their blood sugar levels. Type 1 diabetes arises when the body no longer produces the blood-sugar-regulating hormone insulin, due to an abnormal immune system attack on insulin-secreting cells.

As a result, people with the disease have to take synthetic insulin -- either through daily injections or an insulin "pump" that is worn outside the body and continuously delivers insulin through a catheter placed under the skin in the abdominal area.

Until now, no studies had looked at whether carb counting is specifically useful to people on insulin pump therapy.

For the new study, researchers led by Dr. Andrea Laurenzi, of San Raffaele Vita-Salute University in Milan, recruited 61 adults on insulin pump therapy. They randomly assigned them to either learn how to count carbohydrates or serve as part of a "control" group.

In sessions with a dietitian, participants in the carb-counting group learned how to calculate the amount of carbohydrates in each of their meals and estimate how much insulin they would need to "cover" those carbs.

After 6 months, Laurenzi's team found, the carb-counters showed a slight reduction in weight and waist size, on average -- possibly, the researchers say, because they were paying closer attention to their diets or exercise habits.

When the researchers looked at the whole carb-counting group, there was no clear effect on hemoglobin A1C levels -- a measure of long-term blood sugar control. But when they focused just on the 20 participants who consistently counted carbs for most of their meals, there was evidence of better blood sugar control.

Mehta, however, said that finding is of "uncertain significance."

And in general, he said, the study had too many limitations to draw firm conclusions. One problem, Mehta noted, is that it's unclear what kind of intervention the control group had -- whether they paid no attention to their carbs, or used another method to estimate them.

Still, he pointed out that keeping tabs on carbs, in some way, is clearly important for people with type 1 diabetes.

"It has been recognized for decades that optimal (blood sugar) control depends on meticulous attention to diet, insulin and exercise," Mehta said.

For people who are interested in learning how to count carbs, there are books and online resources. But some people have difficulty learning or sticking with the method, Mehta noted, and help from a professional -- such as a dietitian or certified diabetes educator -- may be needed.